Stab wound & tourniquet

First aid for a stab wound

1. First look after your own safety: do not intervene where there is violence, keep your distance and only help once it is safe.
2. Call or have someone call the 144 emergency number (ambulance) and report that it is a stab injury. If violence is involved, also alert the police on 117.
3. Do not pull out an object lodged in the wound.
4. Press firmly and directly on the bleeding site with your hand, a dressing or a clean piece of cloth – without stopping and without checking in between, until the emergency services take over.
5. Open the person's clothing and search the whole body for further wounds, including the back and armpits.
6. On an arm or leg: if life-threatening bleeding does not stop despite firm pressure, apply a tourniquet – provided one is available and you have practised with it.
7. At the groin, armpit or neck: if a deep wound is bleeding heavily, press a dressing or clean cloth into the wound and then press firmly on top of it.
8. On the chest: do not seal the wound airtight – no film, no plastic, nothing taped all the way around. If it bleeds, press on it without sealing it all the way round.
9. Lay the person flat on their back without elevating the legs; anyone who is conscious after a chest wound and is struggling to breathe may choose the position in which breathing is easiest.
10. Cover them, protect them from cold from underneath too, reassure them and give nothing to eat or drink.
11. Stay with the person and watch their breathing and consciousness. If they stop responding and are not breathing normally, start resuscitation and follow the instructions of the emergency call centre.

Why you leave a lodged object in the wound

An object lodged in a stab wound can seal the wound from the inside and so slow the bleeding. If it is pulled out, heavy bleeding can start. Experts therefore consistently advise leaving it in the wound and only stabilising it.

The recommendation is not based on studies but on expert consensus, as set out in, among others, the international first-aid guideline of the Red Cross (IFRC 2025).

1. Pad around the object, for example with rolled dressings or cloth, so it cannot move
2. Apply pressure against the bleeding around the object, on top of the padding
3. If an object in the chest moves in time with the heartbeat, only stabilise it loosely and do not tie it down

Warning signs: when a stab wound is life-threatening

1. Blood flows quickly or spurts from the wound
2. A pool of blood forms on the ground
3. The bleeding does not stop despite firm pressure
4. Signs of shock: pale, cool or clammy skin, a very fast pulse, dizziness or confusion
5. Increasing drowsiness, progressing to unconsciousness
6. Shortness of breath, painful breathing, coughing up blood or blue lips – signs of a chest injury

Stab wound to the abdomen

A stab wound to the abdomen can injure internal organs and large blood vessels. Bleeding inside the abdomen cannot be stopped from the outside and needs hospital treatment – calling 144 quickly is therefore the most important help.

These measures, too, rest on expert consensus; there are no studies on this.

1. Stop external bleeding by applying pressure to the wound
2. Do not push protruding organs back into the abdomen
3. Cover them with a clean, moist cloth or a moist dressing
4. Help the person lie down and bend their knees – this relaxes the abdomen
5. Give nothing to eat or drink – surgery under anaesthesia may be needed

What is a tourniquet?

A tourniquet is a wide band with a windlass or another tensioning fastener that is tightened around an arm or leg above a wound until no more blood reaches the wound. The name comes from the French «tourner» (to turn); in 1882 Friedrich von Esmarch also called it «Aderpresse» (literally: blood-vessel press) in his guide for Samaritans.

A tourniquet is intended for life-threatening bleeding from an arm or leg – not for small bleeds and never for the neck, armpit, groin, chest or abdomen, because it cannot be applied there.

Commercial tourniquets with a windlass are easier to apply and stop blood flow more reliably than improvised ones; there is no evidence that any particular model is better than the others.

The evidence is weak: there are only observational studies of very low certainty, and a 2025 meta-analysis found no statistically significant survival benefit. Despite this, the major first-aid guidelines – the European one (ERC 2025), the Red Cross one (IFRC 2025) and the American one (AHA/Red Cross 2024) – call for a tourniquet in life-threatening bleeding from an arm or leg when firm pressure does not stop it.

Where did the tourniquet come from? A short history

Stopping bleeding from an arm or leg by constriction is an old idea. During the siege of Besançon in 1674, a French military surgeon is said to have stopped a bleed with a band twisted tight with a stick – the principle behind today's windlass. In 1718 the French surgeon Jean-Louis Petit presented a screw tourniquet to the Academy of Sciences in Paris.

Friedrich von Esmarch introduced «artificial bloodlessness» for operations in 1873. In 1882 he described a windlass tourniquet for lay people in his guide for Samaritan schools: a cloth under which a windlass is pushed and turned «until the bleeding stops».

In the 20th century the tourniquet fell into disrepute: it was often applied incorrectly and left on for hours during long transports. The earlier instruction to loosen it regularly was abandoned during the Second World War because injured people gradually lost blood as a result; since then only medical professionals remove it. For a long time it was seen as a last resort.

Analyses from the Iraq war, published in 2008 and 2009, supported the idea that early tourniquet use saves lives: casualties who received a tourniquet before going into shock survived far more often, and no arm or leg was lost purely because of the tourniquet. Civilian teaching followed: in 2013 the Hartford Consensus laid the groundwork in the USA for lay people, too, to stop life-threatening bleeding, and on 6 October 2015 the White House launched the «Stop the Bleed» campaign. Today the European first-aid guideline ERC 2025 explicitly recommends the tourniquet to first-aiders as well – for life-threatening bleeding from an arm or leg that does not stop with pressure.

Applying a tourniquet: step by step

A tourniquet belongs on an arm or leg when life-threatening bleeding does not stop with firm pressure, when pressure is not possible or cannot be kept up – for example because you alone are caring for several injured people or have to move the person out of danger – or when an arm or leg is fully or partly severed above the wrist or ankle. Only use it if you have practised with it.

1. Warn the injured person in advance: applying it hurts – the pain is not a sign that you are doing it wrong.
2. Place the tourniquet 5⁠–⁠7 cm above the wound (on the side towards the heart) around the arm or leg, not over a joint.
3. Apply it directly onto the skin if possible; if that is not quick enough, over thin clothing too – but not over pockets with objects in them.
4. Pull the band tight and fasten it.
5. Turn the windlass until the bleeding stops.
6. Secure the windlass in its holder so it cannot turn back.
7. Write the time on the tourniquet.
8. Leave the tourniquet visible and in place until the emergency services take over – do not loosen it, do not remove it.
9. If it keeps bleeding: tighten the windlass further. If that is not enough, apply a second tourniquet directly above the first.
10. Tell the emergency services the time it was applied.

Tourniquet: limits and common mistakes

1. Only on an arm or leg – never on the neck, armpit, groin, chest or abdomen
2. Not for small bleeds that stop with pressure
3. Most common mistake in one study: not tightened enough. An improvised band that does not fully stop blood flow can even make the bleeding worse
4. Do not place it over a joint such as the elbow or knee
5. Do not loosen it in between – that costs extra blood
6. Do not forget the time, and do not cover the tourniquet with clothing or a blanket
7. A venous tourniquet strap, a cord, a wire or a cable tie are not suitable as a tourniquet
8. Children: commercial windlass tourniquets can be used from about age 2; if an arm or leg is too thin, press firmly on the wound
9. Only buy from a specialist retailer or the manufacturer: counterfeits are frequently offered online and can fail under load

No tourniquet on hand: keep pressing, improvise only as a last resort

Without a tourniquet, the most important measure is to keep pressing firmly on the wound; for a deep wound, push cloth into it and press firmly on top.

An improvised tourniquet is only a stopgap. In model trials, improvised bands stopped blood flow markedly less often than commercial tourniquets, and without a windlass they failed in 79 of 80 tests in one study. Whether an ordinary trouser belt works is not proven. The 2021 European guideline provided for improvisation only by helpers who have practised it.

1. Only if firm pressure does not stop life-threatening bleeding from an arm or leg and no tourniquet is available: take a wide cloth, at least about 5 cm wide
2. Place it 5⁠–⁠7 cm above the wound around the arm or leg, not over a joint, and knot it
3. Slide a rigid stick underneath as a windlass and turn it until the bleeding stops
4. Secure the stick so it cannot turn back, and note the time

What helps where? Tourniquet, pressure or leaving the wound open

Whether a tourniquet helps depends on where the stab wound is. Firm pressure on the bleeding site is the first measure everywhere.

Stab wound to the chest: how to help

A stab wound to the chest can injure the lung, heart or large blood vessels. How severe the injury is cannot be judged from the outside: even a small wound that neither bubbles nor hisses can be life-threatening.

1. Call 144 immediately – every stab wound to the chest or back is an emergency.
2. Expose the upper body and search the whole torso, including the back and armpits; there may be more than one wound.
3. Leave the wound open: do not seal it with film, plastic or tape and do not tape anything all the way around it.
4. If the wound is bleeding heavily: press a dressing or clean cloth on with the flat of your hand, without sealing the wound all the way round.
5. Do not pull out a lodged object and pad around it; if it moves with the heartbeat, only stabilise it loosely.
6. If the person is conscious and struggling to breathe, let them choose the position in which they breathe best – usually sitting or half-sitting.
7. If they show signs of shock or become increasingly drowsy, lay them flat on their back.
8. Keep them warm, reassure them, stay with them and continuously watch breathing, lip colour and consciousness.
9. If breathing gets worse and something is lying on the wound, remove it immediately and inform 144 again.
10. If the person does not respond and is not breathing normally: start resuscitation, have someone fetch a defibrillator (AED) and follow the instructions of the emergency call centre.

Stab wound to the chest: warning signs

1. Increasing shortness of breath – the most important warning sign
2. Painful breathing or coughing up blood
3. Blue lips, fingernails or skin
4. A wound that bubbles or hisses when breathing (a so-called sucking chest wound)
5. Signs of shock: pale, cool or clammy skin, a very fast pulse, dizziness or confusion
6. Increasing drowsiness

Open chest wound: why lay people leave it open – and the military seals it

The European first-aid guideline ERC 2025 is clear: an open chest wound stays open, so that it stays freely connected to the surrounding air; no dressing, no covering. If it bleeds, the bleeding is stopped with direct pressure. The reason: a dressing that accidentally seals the wound airtight can trigger a life-threatening tension pneumothorax.

A special valved dressing (chest seal), which lets air escape on breathing out, is only provided for by ERC 2025 for helpers who are trained for it and have one with them. The American guideline (AHA/Red Cross 2024) also considers a clean, dry, non-occlusive cloth acceptable – but requires it to be loosened or removed as soon as breathing gets worse. Even a loose dressing can become sealed by blood.

Military medical guidelines (TCCC), by contrast, apply a chest seal immediately – with matching equipment, training and specialist personnel able to relieve a pressure build-up in the chest. That is a professional standard under different conditions, not the teaching for lay people. The home-made three-sided plastic-film dressing taught in the past is considered unreliable and is no longer intended for lay people.

The evidence base is thin: there are no conclusive studies in injured people for any lay measure for an open chest wound; the recommendations rest mainly on animal experiments and expert consensus. The last evidence review by the international expert body ILCOR dates from 2022.

Unconscious after a stab wound: leave them on their back

1. An unconscious injured person who is breathing normally stays lying on their back – the European guideline ERC 2025 does not provide for the recovery position in injured people
2. Only move the person if they are in danger where they are
3. Constantly watch their breathing and follow the instructions of the emergency call centre
4. If the unconscious person stops breathing normally: start resuscitation
5. Do not immobilise the neck just because of a stab wound – for pure stab injuries, guidelines advise against this

Myths and outdated teaching

1. «Raise the bleeding body part»: there is no evidence of benefit, but it can cause more pain or injury
2. «Always put the legs up for shock»: not in injured people – the guidelines only call for elevating the legs when there is no injury
3. «Press on a pressure point instead of the wound»: explicitly not recommended; in a study of healthy volunteers, the pulse below the pressure point was back after just 20 to 40 seconds
4. «A tourniquet costs you the leg»: not proven for short application times; the risk rises with hours-long application and with unnecessary use
5. «Loosen a tourniquet regularly»: outdated – loosening it costs extra blood
6. «The tourniquet must come off after two hours»: no rule for lay people – the two-hour mark comes from military guidelines for trained personnel
7. «A belt or cord is enough»: narrow bands work worse, and without a windlass improvised bands failed almost every time in one study
8. «Seal an open chest wound airtight»: outdated for lay people – the wound stays open
9. «Quickly remove a lodged object»: no – it stays in the wound

After first aid: what you tell the emergency services

1. What happened and how many wounds you found
2. What you did: pressure, tourniquet, object left in the wound
3. The time a tourniquet was applied
4. How breathing, consciousness and skin colour have changed

Being prepared: emergency numbers, course and equipment in Switzerland

1. Emergency numbers: 144 ambulance, 117 police, 112 European emergency number (connects to the police control centre in Switzerland), 1414 Rega
2. In Switzerland the tourniquet is part of the syllabus from the «First Aid Level 2 IVR» course onward (21 hours; the prerequisite is Level 1 or a BLS-AED course together with the emergency first-aid course); the description of the emergency first-aid course for the driving licence does not mention it
3. A tourniquet is only useful if you have practised with it: the guidelines advise using only equipment you have been trained with
4. Disposable gloves protect against blood; if you don't have any, cover your hands with a plastic bag or cloth – but do not delay applying pressure because of this
5. The Criminal Code (Art. 128 SCC) requires you to help a person in immediate life-threatening danger, as far as can reasonably be expected in the circumstances

Frequently asked questions

Further sources

• Injured persons Applying a pressure bandage and recognising shock
• Accident Look – Think – Act and the 144 emergency call
• Unconscious persons Checking breathing when the person does not respond
• Resuscitation When the injured person is no longer breathing normally
• Guide: Home medicine cabinet Keeping dressing material ready for severe bleeding
• Guide: Reporting clearly with SALUTE and the W-questions What you report during the 144 emergency call
• Guide: Protection in terror & violence Run – Hide – Tell: your own safety first
• Behaviour: Psychological first aid and where to find professional help After the shock: supporting those affected and yourself
• ERC guidelines 2025: first aid European first-aid guideline
• IFRC guidelines 2025 First-aid guideline of the Red Cross movement (PDF)
• AHA/American Red Cross 2024 US first-aid guideline
• Swiss Samaritans First aid for bleeding (German)
• Swiss Samaritans: First Aid Level 2 IVR Course with tourniquet training (German)
• Stop the Bleed US programme: learn to stop bleeding
• Richey 2007: Tourniquets Review article including the history of the tourniquet
• Esmarch 1882: Die erste Hülfe Guide for Samaritan schools (digitised, German)